U.S. patent number 9,455,568 [Application Number 14/253,095] was granted by the patent office on 2016-09-27 for energy storage system for renewable energy source.
This patent grant is currently assigned to General Electric Company. The grantee listed for this patent is General Electric Company. Invention is credited to Rafael Ignacio Bedia, Anthony Michael Klodowski, Benjamin Arthur Niemoeller, Steven Wade Sutherland, Robert Gregory Wagoner.
United States Patent |
9,455,568 |
Wagoner , et al. |
September 27, 2016 |
Energy storage system for renewable energy source
Abstract
Renewable energy power systems, DC to DC converters, and methods
for operating energy storage systems are provided. A system
includes a power converter having a DC bus, and an energy storage
system coupled to the DC bus of the power converter. The energy
storage system includes an energy storage device and a switching
power supply coupled between the energy storage device and the DC
bus of the power converter. The switching power supply includes a
plurality of switching elements, and an energy storage device
protection circuit coupled between the plurality of switching
elements and the energy storage device, the energy storage device
protection circuit including a solid state switch. The switching
power supply further includes a fuse coupled to the energy storage
device protection circuit.
Inventors: |
Wagoner; Robert Gregory
(Roanoke, VA), Klodowski; Anthony Michael (Hardy, VA),
Sutherland; Steven Wade (Roanoke, VA), Bedia; Rafael
Ignacio (Roanoke, VA), Niemoeller; Benjamin Arthur (Cave
Spring, VA) |
Applicant: |
Name |
City |
State |
Country |
Type |
General Electric Company |
Schenectady |
NY |
US |
|
|
Assignee: |
General Electric Company
(Schenectady, NY)
|
Family
ID: |
54265867 |
Appl.
No.: |
14/253,095 |
Filed: |
April 15, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20150295398 A1 |
Oct 15, 2015 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J
3/386 (20130101); H02J 3/381 (20130101); H02H
7/1213 (20130101); H02J 3/32 (20130101); H02J
7/0029 (20130101); H02J 7/00304 (20200101); H02J
7/0031 (20130101); Y02E 10/76 (20130101); H02J
7/00 (20130101); Y02E 10/763 (20130101); H02J
2300/28 (20200101); H02H 7/18 (20130101); H02J
2207/20 (20200101); Y02E 70/30 (20130101) |
Current International
Class: |
H02H
7/12 (20060101); H02M 3/00 (20060101); H02J
7/00 (20060101); H02J 3/32 (20060101); H02J
3/38 (20060101); H02H 7/18 (20060101) |
Field of
Search: |
;363/132,37,47,98
;361/104 ;318/370-389 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Han; Jessica
Assistant Examiner: Gibson; Demetries A
Attorney, Agent or Firm: Dority & Manning, P.A.
Claims
What is claimed is:
1. A renewable energy power system, comprising: A DC to DC power
converter having a DC bus; a battery energy storage system coupled
to the DC bus of the power converter, the battery energy storage
system comprising an energy storage device and a switching power
supply coupled between the energy storage device and the DC bus of
the power converter, the switching power supply comprising: a
plurality of switching elements; an energy storage device
protection circuit coupled between the plurality of switching
elements and the energy storage device, the energy storage device
protection circuit comprising a solid state switch and a
antiparallel diode coupled in parallel with the solid state switch,
the solid state switch comprising an anode, a cathode, and a gate;
and a fuse coupled to the energy storage device protection
circuit.
2. The renewable energy power system of claim 1, wherein the energy
storage device protection circuit further comprises a resistor
coupled in series with the solid state switch.
3. The renewable energy power system of claim 1, wherein the solid
state switch is a silicon-controlled rectifier.
4. The renewable energy power system of claim 1, wherein the
plurality of switching elements comprise a first switching element
and a second switching element coupled in series with one
another.
5. The renewable energy power system of claim 4, wherein the fuse
is coupled to a node between the first switching element and the
second switching element.
6. The renewable energy power system of claim 4, wherein the fuse
is coupled to a positive terminal of the DC bus.
7. The renewable energy power system of claim 1, wherein the energy
storage device comprises a battery module, the battery module
comprising a first switch, a battery, a second switch, and a fuse
coupled in series to the first switch.
8. The renewable energy power system of claim 1, wherein the
switching power supply further comprises a normal mode filter
coupled between the plurality of switching elements and the energy
storage device protection circuit, and a common mode filter coupled
between the normal mode filter and the energy storage device
protection circuit.
9. A DC to DC power converter comprising: a first transistor having
a gate, a collector, and an emitter; a second transistor having a
gate, a collector, and an emitter, the collector of the second
transistor being coupled to the emitter of the first transistor; an
energy storage device protection circuit, the energy storage device
protection circuit comprising a solid state switch and an
antiparallel diode coupled in parallel with one another, the solid
state switch comprising an anode, a cathode, and a gate; and a
plurality of fuses coupled to the energy storage device protection
circuit.
10. The DC to DC power converter of claim 9, wherein the plurality
of fuses comprises a fuse coupled to a node between the first
transistor and the second transistor.
11. The DC to DC power converter of claim 9, wherein the plurality
of fuses comprises a fuse coupled to the collector of the first
transistor.
12. The DC to DC power converter of claim 11, further comprising a
breaker coupled between the first transistor and the fuse.
13. The DC to DC power converter of claim 9, wherein the solid
state switch is a silicon-controlled rectifier.
14. The DC to DC power converter of claim 9, wherein the energy
storage device protection circuit further comprises a resistor
coupled in series with the solid state switch and the antiparallel
diode.
15. The DC to DC power converter of claim 9, further comprising a
normal mode filter coupled between the first and second transistors
and the energy storage device protection circuit, and a common mode
filter coupled between the normal mode filter and the energy
storage device protection circuit.
16. A method of operating an energy storage system, the method
comprising: providing power between a DC bus and an energy storage
device via a DC to DC power converter coupled between the DC bus
and the energy storage device; while providing power, firing a
solid state switch of the DC to DC power converter when an
overvoltage event occurs, the solid state switch comprising an
anode, a cathode, and a gate; and providing a path for current flow
through an antiparallel diode of the DC to DC converter when the
overvoltage event is negative, the antiparallel diode coupled in
parallel with the solid state switch.
17. The method of claim 16, wherein the power is provided through a
plurality of switching elements of the DC to DC converter.
18. The method of claim 17, further comprising clearing a fuse
coupled between the plurality of switching elements and the solid
state switch when the overvoltage event exceeds a predetermined
threshold.
19. The method of claim 18, wherein the predetermined threshold is
below a voltage rating for the solid state switch.
Description
FIELD OF THE INVENTION
The present disclosure relates generally to renewable energy power
systems, and more particular to an energy storage system for use in
a renewable energy power system.
BACKGROUND OF THE INVENTION
Renewable energy power systems, such as wind energy power systems
and solar energy power systems, often include a power converter
with a regulated DC bus. For example, wind power systems, such as
wind driven doubly-fed induction generator (DFIG) systems or full
power conversion systems, can include a power converter with an
AC-DC-AC topology. Solar power systems can include a power
converter that has a DC-DC-AC topology or simply a DC-AC
topology.
An energy storage system can be coupled to the DC bus of a power
converter in a renewable energy power system. The energy storage
system can be used, for instance, to apply power to the DC bus of
the power converter during transient conditions. A switching power
supply can be provided to transfer energy back and forth between
the DC bus of the power converter and the energy storage device.
For instance, the switching power supply can include a DC to DC
converter configured to convert a first voltage on the DC bus to a
second voltage at the energy storage device, and vice versa. It can
be desirable for the switching power supply to be bi-directional to
allow not only for power flow from the energy storage device to the
DC bus during transient conditions but also to allow power flow
from the DC bus to the energy storage device, for instance, to
charge the energy storage device.
One issue that needs to be addressed with respect to the energy
storage systems is the protection of the energy storage device from
switching power supply faults. For example, if a component in the
switching power supply such as a switching element fails, positive
and/or negative voltage surges can be experienced in the switching
power supply and transmitted to the energy storage device.
Protection from such overvoltage and negative voltage events would
be advantageous. Accordingly, improved energy storage systems and
switching power supplies thereof, which provide improved fault
protection, are desired in the art.
BRIEF DESCRIPTION OF THE INVENTION
Aspects and advantages of the invention will be set forth in part
in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
In accordance with one embodiment, a renewable energy power system
is provided. The system includes a power converter having a DC bus,
and an energy storage system coupled to the DC bus of the power
converter. The energy storage system includes an energy storage
device and a switching power supply coupled between the energy
storage device and the DC bus of the power converter. The switching
power supply includes a plurality of switching elements, and an
energy storage device protection circuit coupled between the
plurality of switching elements and the energy storage device, the
energy storage device protection circuit including a solid state
switch. The switching power supply further includes a fuse coupled
to the energy storage device protection circuit.
In accordance with another embodiment, a DC to DC power converter
is provided. The DC to DC power converter includes a first
transistor having a gate, a collector, and an emitter, and a second
transistor having a gate, a collector, and an emitter, the
collector of the second transistor being coupled to the emitter of
the first transistor. The DC to DC power converter further includes
an energy storage device protection circuit, the energy storage
device protection circuit including a solid state switch and an
antiparallel diode coupled in parallel with one another. The DC to
DC power converter further includes a plurality of fuses coupled to
the energy storage device protection circuit.
In accordance with another embodiment, a method of operating an
energy storage system is provided. The method includes providing
power between a DC bus and an energy storage device via a DC to DC
converter coupled between the DC bus and the energy storage device.
The method further includes firing a solid state switch of the DC
to DC converter when an overvoltage event occurs, and providing a
path for current flow through an antiparallel diode of the DC to DC
converter when a negative voltage event occurs. The antiparallel
diode is coupled in parallel with the solid state switch.
Variations and modifications can be made to these example
embodiments of the present disclosure.
These and other features, aspects and advantages of the present
invention will become better understood with reference to the
following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present invention, including
the best mode thereof, directed to one of ordinary skill in the
art, is set forth in the specification, which makes reference to
the appended figures, in which:
FIG. 1 depicts an example renewable energy power system according
to example embodiments of the present disclosure;
FIG. 2 depicts an example energy storage system coupled to the DC
bus of a power converter according to example embodiments of the
present disclosure;
FIG. 3 depicts example topology for an example switching power
supply for an energy storage system according to example
embodiments of the present disclosure; and
FIG. 4 depicts a flow diagram of an example method of operating an
energy storage system according to example embodiments of the
present disclosure.
DETAILED DESCRIPTION OF THE INVENTION
Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
Generally, example aspects of the present disclosure are directed
to energy storage systems for use in renewable energy power
systems. More particularly, an energy storage system can be coupled
to the DC bus of a power converter used in a renewable energy power
system. For example, the energy storage system can be coupled to
the DC bus of an AC to DC to AC converter used in a wind energy
power system. As another example, the renewable energy storage
system can be coupled to the DC bus of a DC to DC to AC converter
used in a solar energy system.
The energy storage system can include an energy storage device,
such as a battery storage device, fuel cell, capacitor, or other
suitable energy storage device. A switching power supply can be
coupled between the energy storage device and the DC bus of the
power converter. A control system can control the switching power
supply to regulate power flow between the energy storage device and
the DC bus. For instance, the switching power supply can be
controlled to convert a first DC voltage at the DC bus to a second
DC voltage at the battery energy storage device.
According to example aspects of the present disclosure, the
switching power supply can include a DC to DC converter. In
particular, bi-directional DC to DC converters may be utilized. In
particular implementations, the DC to DC converter can include a
topology that includes a first switching element and a second
switching element coupled in series with one another. The first
switching element can be a first insulated gate bipolar transistor
(IGBT) having a gate, a collector, and an emitter. The second
switching element can be a second insulated gate bipolar transistor
(IGBT) having a gate, a collector, and an emitter. The collector of
the first IGBT can be coupled to a positive terminal of the DC bus.
The emitter of the first IGBT can be coupled to the collector of
the second IGBT. The emitter of the second IGBT can be coupled to a
negative terminal of the DC bus. A first diode can be coupled in
parallel with the first IGBT. A second diode can be coupled in
parallel with the second IGBT.
According to particular aspects of the present disclosure, a
bi-directional converter can be configured to accommodate power
flow in two directions. For instance, a control system can operate
the energy storage system in a first mode such that power flows in
a first direction from the DC bus to the energy storage device, for
instance, to charge the energy storage device. The control system
can also be configured to operate the energy storage system in a
second mode such that power flows in a second direction from the
energy storage device to the DC bus, for instance, to provide
supplemental power to the DC bus during transient conditions (e.g.
a reduction in wind in a wind energy system or a reduction in
sunlight in a solar energy system).
The switching power supply, such as the DC to DC converter, can
also advantageously include various components which may operate to
protect the energy storage device in the event of switching power
supply faults, which may result in overvoltage events and/or
negative voltage events. An overvoltage event is generally any
period during which voltages flowing through the switching power
supply exceed a predetermined limit for the energy storage device.
A negative voltage event is generally any period during which
voltages flowing through the switching power supply are
negative.
For example, the switching power supply may include an energy
storage device protection circuit. The energy storage device
protection circuit may include, for example, a solid state switch,
such as in exemplary embodiments a silicon-controlled rectifier
("SCR"). Additionally, an anti-parallel diode may be coupled in
parallel to the solid state switch, and a resistor may be coupled
in series with the solid state switch and anti-parallel diode.
Additionally, the switching power supply may include various fuses
which are sized to protect other components of the switching power
supply, such as the energy storage protection circuit. For example,
fuses may be coupled between the switching power supply and the
switching elements. These fuses may be sized to clear at voltage
levels which are below, for example, the rated maximum voltage of
the solid state switch. Additionally, a fuse may be coupled in the
energy storage device.
With reference now to the FIGS., example embodiments of the present
disclosure will now be discussed in detail. FIG. 1 depicts an
example wind driven doubly-fed induction generator (DFIG) system
100. Example aspects of the present disclosure are discussed with
reference to the DFIG wind turbine system 100 of FIG. 1 for
purposes of illustration and discussion. Those of ordinary skill in
the art, using the disclosures provided herein, should understand
that example aspects of the present disclosure are also applicable
in other power systems, such as a wind, solar, gas turbine, or
other suitable power generation system.
In the example system 100, a rotor 106 includes a plurality of
rotor blades 108 coupled to a rotating hub 110, and together define
a propeller, such as of a wind turbine. The propeller is coupled to
an optional gear box 118, which is, in turn, coupled to a generator
120. In accordance with aspects of the present disclosure, the
generator 120 is a doubly fed induction generator (DFIG) 120.
DFIG 120 is typically coupled to a stator bus 154 and a power
converter 162 via a rotor bus 156. The stator bus 154 provides an
output multiphase power (e.g. three-phase power) from a stator of
DFIG 120 and the rotor bus 156 provides an output multiphase power
(e.g. three-phase power) of a rotor of the DFIG 120. Referring to
the power converter 162, DFIG 120 is coupled via the rotor bus 156
to a rotor side converter 166. The rotor side converter 166 is
coupled to a line side converter 168 which in turn is coupled to a
line side bus 188.
In example configurations, the rotor side converter 166 and the
line side converter 168 are configured for normal operating mode in
a three-phase, pulse width modulation (PWM) arrangement using
insulated gate bipolar transistor (IGBT) switching elements. The
rotor side converter 166 and the line side converter 168 can be
coupled via a DC bus 136 across which is the DC bus capacitor
138.
The power converter 162 can be coupled to a control system 174 to
control the operation of the rotor side converter 166 and the line
side converter 168 and other aspects of the power system 100. The
control system 174 can include any number of control devices. In
one implementation, the control system 174 can include a processing
device (e.g. microprocessor, microcontroller, etc.) executing
computer-readable instructions stored in a computer-readable
medium. The instructions when executed by the processing device can
cause the processing device to perform operations, including
providing control commands (e.g. pulse width modulation commands)
to the switching elements of the power converter 162 and in other
aspects of the power system 100, such as a power switching supply
used in an energy storage system 200.
In operation, alternating current power generated at DFIG 120 by
rotation of the rotor 106 is provided via a dual path to electrical
grid 160. The dual paths are defined by the stator bus 154 and the
rotor bus 156. On the rotor bus side 156, sinusoidal multi-phase
(e.g. three-phase) alternating current (AC) power is provided to
the power converter 162. The rotor side power converter 166
converts the AC power provided from the rotor bus 156 into direct
current (DC) power and provides the DC power to the DC bus 136.
Switching elements (e.g. IGBTs) used in bridge circuits of the
rotor side power converter 166 can be modulated to convert the AC
power provided from the rotor bus 156 into DC power suitable for
the DC bus 136.
The line side converter 168 converts the DC power on the DC bus 136
into AC output power suitable for the electrical grid 160. In
particular, switching elements (e.g. IGBTs) used in bridge circuits
of the line side power converter 168 can be modulated to convert
the DC power on the DC bus 136 into AC power on the line side bus
188. The AC power from the power converter 162 can be combined with
the power from the stator of DFIG 120 to provide multi-phase power
(e.g. three-phase power) having a frequency maintained
substantially at the frequency of the electrical grid 160 (e.g. 50
Hz/60 Hz).
Various circuit breakers and switches, such as a converter breaker
186, can be included in the system 100 to connect or disconnect
corresponding buses, for example, when current flow is excessive
and can damage components of the wind turbine system 100 or for
other operational considerations. Additional protection components
can also be included in the wind turbine system 100.
The power converter 162 can receive control signals from, for
instance, the control system 174. The control signals can be based,
among other things, on sensed conditions or operating
characteristics of the wind turbine system 100. Typically, the
control signals provide for control of the operation of the power
converter 162. For example, feedback in the form of sensed speed of
the DFIG 120 can be used to control the conversion of the output
power from the rotor bus 156 to maintain a proper and balanced
multi-phase (e.g. three-phase) power supply. Other feedback from
other sensors can also be used by the controller 174 to control the
power converter 162, including, for example, stator and rotor bus
voltages and current feedbacks. Using the various forms of feedback
information, switching control signals (e.g. gate timing commands
for IGBTs), stator synchronizing control signals, and circuit
breaker signals can be generated.
According to example aspects of the present disclosure, a battery
energy storage system 200 can be coupled to the power converter 162
of the power system 100. The present disclosure is discussed with
reference to a battery energy storage system for purposes of
illustration and discussion. Those of ordinary skill in the art,
using the disclosures provided herein, should understand that
aspects of the present disclosure are also applicable in other
energy storage systems.
The battery energy storage system 200 can be coupled to the DC bus
136 of the power converter 162. The energy storage system 200 can
be used to provide power to the DC bus 136 under certain
conditions. For instance, the energy storage system 200 can be used
to provide power to the DC bus 136 to increase output of the power
system 100 when wind speed drops. Power can also be supplied and
stored in the energy storage system 200 during operation of the
DFIG system 100.
FIG. 2 depicts an example battery energy storage system 200 coupled
to the DC bus 136 of a power converter 162. The battery energy
storage system 200 can include a battery energy storage device 210.
The battery energy storage device 210 can be coupled to the DC bus
136 via a switching power supply 220, such as a DC to DC converter.
The switching power supply 220 can convert the DC power on the DC
bus to a DC voltage that is suitable for application to the battery
energy storage device 210.
The switching power supply 220 can include a plurality of switching
elements (e.g. IGBTs or other switching elements). The switching
elements can be controlled, for instance, by control system 174
(FIG. 1) to regulate power flow in the energy storage system 200.
For example, during times of high power output, a first switching
element can be controlled such that power flows in a first
direction from the DC bus 136 to the energy storage device 210 to
charge the energy storage device 210. During times of low power
output, a second switching element can be controlled such that
power flows in a second direction from the energy storage device
210 to the DC bus 136 for use in boosting output of the power
system.
According to particular aspects of the present disclosure, the
switching power supply 220 can be a DC to DC converter, such as a
bi-directional DC to DC converter. The DC to DC converter can be
configured to convert a first DC voltage at the DC bus 136 to a
second DC voltage at the energy storage device 210. In particular
embodiments, the bi-directional DC to DC converter can be any
converter capable of accommodating power flow in two
directions.
FIG. 3 depicts example topology for a DC to DC converter 300 that
can be used as a switching power supply according to example
aspects of the present disclosure. The DC to DC converter 300 can
include a bridge circuit 310 coupled to a DC bus 136. The DC bus
136 can have a positive terminal 144 and a negative terminal 146
The bridge circuit 310 can include a first switching element 312
and a second switching element 314 coupled in series with one
another. The first switching element 312 and the second switching
element 314 can be any suitable switching device, such as an IGBT,
power MOSFET, or other suitable switching device.
For instance, the first switching element 312 can be a first IGBT
having a gate, a collector, and an emitter. The second switching
element 314 can be a second IGBT having a gate, a collector, and an
emitter. The collector of the first IGBT 312 can be coupled to the
positive terminal 144 of the DC bus 136. The emitter of the first
IGBT 312 can be coupled to the collector of the second IGBT 314.
The emitter of the second IGBT can be coupled to the negative
terminal 146 of the DC bus 136.
The first switching element 312 can be coupled to a first
antiparallel diode 322. The second switching element 314 can be
coupled to a second antiparallel diode. One or more of the first
switching element 312 and the second switching element 314 can be
controlled to convert a first DC voltage V.sub.DC on the DC bus 136
to a second DC voltage V.sub.OUT at the energy storage device. More
particularly, pulse width modulation commands (e.g. gate drive
commands) can be provided to the first switching element 312 or the
second switching element 314 to adjust the pulse width of the DC to
DC converter to regulate power flow between the DC bus 136 and an
energy storage device.
The DC to DC converter 300 may further include an energy storage
device protection circuit 330. Circuit 330 protects the energy
storage device 210 and system 200 in the event of switching power
supply faults and resulting overvoltage events and/or negative
voltage events. As illustrated, circuit 330 includes solid state
switch 332. In the embodiment illustrated, solid state switch 332
is an SCR, although in alternative embodiments any suitable solid
state switch may be utilized. The switch 332 may be fired when an
overvoltage event occurs. Accordingly if the voltage in converter
300 increases above a predetermined threshold for the switch, the
switch may fire. This protects the device 210 in overvoltage
events.
An anti-parallel diode 334 may additionally be included in the
circuit 330, and may be coupled in parallel with the solid state
switch 332. Anti-parallel diode 334 may protect the device 210
during negative voltage events, by providing a path for current
flow through the circuit 330 and system generally.
Further, as illustrated, a resistor 336 may be included in the
circuit 330. Resistor 336 may be coupled in series with the switch
332 and the diode 334.
Various filters may be included in the converter 300. The filters
may generally filter the output of the plurality of switching
elements to provide an output DC current and output DC voltage at
the energy storage device 210. For example, a normal mode filter
340 can be coupled between the plurality of switching elements and
the circuit 330. Additionally or alternatively, a common mode
filter 345 may be coupled between the plurality of switching
elements and the circuit 330, such as between the normal mode
filter 340 and the circuit 330. It should be understood that the
normal mode filter 340 and common mode filter 345 are not limited
to the components and arrangements thereof as illustrated in FIG.
3, and rather that any suitable normal mode filter 340 and/or
common mode filter 345 having more or less components in any
suitable arrangement are within the scope and spirit of the present
disclosure.
Various fuses may additionally be provided in the DC to DC power
converter 300, to protect the device 210 and the various other
components of the converter 300. In particular, fuses may be
coupled between the plurality of switching elements and the solid
state switch 332. For example, a fuse 350 may be coupled to node
315 between the first and second switching elements. Additionally
or alternatively, a fuse 352 may be coupled to the positive
terminal 144 of the DC bus 136, such as to the collector of the
first switching element in embodiments wherein the switching
element is a transistor. Notably, in some embodiments, a breaker
356 may be coupled between one or more of the switching elements
and the fuse(s) 350, 352. Breaker 356 may for example, be coupled
between the first switching element 312 and one or both fuses 350,
352. Both fuses may be operable to clear at predetermined
thresholds. In exemplary embodiments, one or both fuses 350, 352
may be operable to clear at predetermined thresholds which are
below a voltage rating for the solid state switch 332. The voltage
rating is a maximum voltage that the switch 332 can handle before
damage is likely to occur. Accordingly, a lower predetermined fuse
threshold may protect the solid state switch 332, as well as other
various components of the DC to DC power converter 300.
Additionally or alternatively, a fuse may be coupled in the energy
storage device 210. For example, as discussed, in some embodiments
the energy storage device 210 is a battery energy storage device
210. The device 210 may include one or more battery modules 360,
which may in the case of two or more be coupled in parallel to each
other. A battery module 360 may include a battery 362, a first
switch 364 and a second switch 366, as illustrated. Further,
battery module 360 may include a fuse 368. The fuse 368 may be
coupled in series to the first switch 364. Fuse 368 may be operable
to clear at a predetermined threshold. In exemplary embodiments,
fuse 368 may be operable to clear at a predetermined threshold
which is below a voltage rating for another component of the
battery module 360, such as the first switch 364. Accordingly, a
lower predetermined fuse threshold may protect the first switch
364, as well as other various components of the battery module
360.
FIG. 4 depicts a flow diagram of an example method 400 for
operating an energy storage system according to an example
embodiment of the present disclosure. The method 400 can be
implemented using any suitable energy storage system, such as the
energy storage system 200 depicted in FIG. 2. In addition, FIG. 4
depicts steps performed in a particular order for purposes of
illustration and discussion. Those of ordinary skill in the art,
using the disclosures provided herein, will understand that various
steps of any of the methods disclosed herein can be adapted,
omitted, rearranged, or expanded in various ways without deviating
from the scope of the present disclosure.
At step 410, a method as illustrated may include providing power
between a DC bus 136 and an energy storage device 210 via a DC to
DC converter 300 coupled between the DC bus 136 and the energy
storage device 210. Power may be provided to the energy storage
device 210 in some embodiments, or alternatively may be provided to
the DC bus 136, as discussed herein. In exemplary embodiments, the
power is provided through a plurality of switching elements, such
as elements 312, 314, of the DC to DC converter 300.
At step 420, a method as illustrated may include firing a solid
state switch 332 of the DC to DC converter 300 when an overvoltage
event occurs, as discussed herein. At step 430, a method as
illustrated may include providing a path for current flow through
an antiparallel diode 334 of the DC to DC converter 300 when a
negative voltage event occurs, as discussed herein.
In some exemplary embodiments, such as at step 440 as illustrated,
a method may further include clearing one or more fuses, such as
fuses 350, 352, coupled between the plurality of switching elements
and the solid state switch 332 when the overvoltage event exceeds a
predetermined threshold. The predetermined threshold may for
example be below a voltage rating for the solid state switch 332.
Additionally or alternatively, a method may further include
clearing one or more fuses, such as fuse 368, coupled in a battery
module 360 when the overvoltage event exceeds a predetermined
threshold. The predetermined threshold may for example be below a
voltage rating for another component of the battery module 360,
such as a switch 364.
This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in
the art to practice the invention, including making and using any
devices or systems and performing any incorporated methods. The
patentable scope of the invention is defined by the claims, and may
include other examples that occur to those skilled in the art. Such
other examples are intended to be within the scope of the claims if
they include structural elements that do not differ from the
literal language of the claims, or if they include equivalent
structural elements with insubstantial differences from the literal
languages of the claims.
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